3D-printed glasses

Sticker shock: Why are glasses so expensive?

The 1910's style (not 1940's 🙂) is a matter of taste. If you don't like it you don't like it. But there are actual advantages to it:

• The lenses are closer to your eyes, providing a huge viewing port with small lenses, limiting chromatic aberration with high index lenses, making lenses thinner with high Rx lenses and making smudges and dirt less visible.
• The frames are narrower, making them less susceptible to damage.

But if the style puts you off, clearly that's a personal preference.

As for your other points:

The frame is by far the cheapest part of a pair of glasses

Depends on the frames. Some are stupendously expensive.

it needs to be durable (this one is not and can not be)

How do you know? Have you tried them?
I wear them every day all the time. They're perfectly durable.

UV resistant (PLA isn’t - why not at least use a better filament?).

My everyday glasses are printed out of PETG, which isn't affected by UVs. My reading glasses - which stay indoors - are printed out of PLA.

But it doesn't matter: if your PLA frames become brittle, no problem: print another set, mount the lenses and off you go. It takes 30 minutes at the most.

You’d think that a proof of concept like this would at least try and make use of the unique advantages inherent to 3D printing to come up with a design that isn’t possible or economically feasible with mass-produced glasses, but there’s none of that here

You totally miss the points of those 3D-printed glasses. They're not a proof of concept and they're not a way to save money on the frames.

What they provide is freedom from opticians. If you break your frames - assuming you didn't damage the lenses obviously - you just print new ones and you resume your life in 30 minutes.

When you rely on an optician, you have to go there (without glasses obviously, good luck driving without glasses with high Rx lenses), order new glasses, often choose new frames because your old frames conveniently don't exist anymore, or the same model is slightly different and your old lenses don't fit them, then you have to wait for days or weeks for the glasses to arrive. And while you're waiting, you have to live without glasses.

Not to mention of course, the frames may be cheap, but if you go to an optician to have new glasses made, more likely than not, you'll need new lenses. That is NOT cheap.

My glasses make me independent from all that. I don't need to wait for new glasses, and I don't have to pay for new lenses if mine are still serviceable. If I sit on my glasses, I get up, fire up the printer, clean the prints a bit with fine grit sandpaper and/or acetone, mount the lense into the new frames, install the hinge pins, and before my wife is done cooking dinner, I have new glasses without ever leaving home for zero dollars.

That's their appeal. Not the price or making 3D-printed everything for the hell of it.

That's also why - as you noticed - I put a lof ot thought into them: I LIVE with them FOR REAL.

I would personally rather trust a professional to fit glasses to my head instead of winging it myself.

You are very wrong about that. The professional is valuable to measure your pupillary distance and vertical angle, and make sure the lenses sit where they should. But glasses that are meticulously customized by yourself to fit your own face are the best glasses you can get.

There's nothing magical about fitting glasses to a person and opticians don't really want to do the final fitting: it's long, it's not optical work per se and they're rather send you on your way asap. When you do that yourself, your glasses will be as good as can be.

I'm extremely happy with my Elegoo Neptune 3 Pro. I got mine for about 165 bucks last year (new) and it looks like you can still find it for about this much.

A few things to do to get decent results out of it (these points also apply to most other 3D printers):

• Spend a couple of hours researching aspects like which print settings to use for which kind of print. Experiment and test - there are all sorts of useful test files on the usual sites.
• Put it in a well ventilated room that you're not spending much time in, especially if your asthmatic. Both noise and air pollution are substantial.
• Calibrate it properly: This printer, unlike its successor, has automatic bed calibration, so this aspect is a breeze.
• Be careful with the belt tensioning. You can accidentally overdo this. Ask me how I found out...
• Get the following small accessories that you will inevitably need: Tweezers, a small wire brush (tooth brush size) to clean the nozzle with, spare nozzles in a few sizes (look up how to change them - the printer needs to be hot for this), cleaning filament (use it any time you're changing between different filament types), a long "clog poke" needle with a proper handle (trust me, you'll need it eventually), a pair of wire cutters (to cut filament), a scraper with plastic blades (to clean up the print bed and remove some especially sticky prints without damaging the bed) and a few sticks of glue for bed adhesion with some materials. A spare PEI bed sheet also makes sense.
• Make sure to use dry filament. No other point on this list has a bigger impact on print quality. This means that a decent filament dryer is mandatory. I went with a Creality Space Pi for about 65 bucks (don't get cheaper models with fake sensors). You can print directly from this dryer, but make sure it's bolted to the desk, since the printer will otherwise pull it across said desk. Store the filament, once dried, in an air-tight and light-protected place. I recommend large plastic cereal boxes with a handful of desiccant each (the type that discolors when it's used up), placed in either cardboard boxes or dark cupboard. If you're feeling fancy, you can place air humidity and temperature sensors in each box. Do all of this and you can achieve prints that rival and even exceed those of machines that cost more than ten times as much a few years ago. Sure, the prints will take about three times as much as on an expensive printer, but having used both, I've been consistently impressed by the quality of the prints this cheap thing manages to achieve.
• Don't buy the cheapest filament possible. Cheaper filament tends to have inconsistent diameters, which can ruin prints. 20 bucks a spool is a good middle ground for normal filament. Fancier materials can cost a lot more, but aren't needed unless you actually need them for a print due to their appearance or other properties. Having said that, inexpensive, but properly dried filament is still superior to expensive filament that was allowed to soak in moisture from the air and get blasted by light for a few weeks.
• This particular printer appears to be ideal for PETG, which is considered a more challenging material to print compared to PLA, but I'm actually getting better results with it more easily than with PLA. Bed adhesion in particular is far superior, to the point that I have to wrangle with some prints to get them off the damn thing. Since it costs about the same per spool and has superior properties (UV, strength, elasticity), it's a no-brainer, especially for functional prints. I doubt I would have been able to print a complex full-size (and quite dangerous) repeating crossbow after a just three weeks of learning to use this printer had I used PLA instead of PETG.
• If you don't want to run to and from your printer with a microSD card with the print files all the time, set up an Octoprint print server. I'm using an older laptop for this, but you can even use Android devices (provided they aren't too slow). This allows you to control the printer over your network - and with a webcam, you can monitor prints in real-time. Octoprint is not trivial to set up, but if you can follow instructions and have at least intermediary computer skills, it's doable.

A word of warning: You need to be able and willing to tinker, experiment and have the ability to deal with failures and issues for this hobby. No printer on the market, including far fancier and more expensive models (I've also worked with those) are trouble-free. If you're the kind of person who has been building and troubleshooting computers since their 12th birthday, you're probably fine, but if you're more the kind of person who buys electronic devices instead of building them and needs help from others any time they go wrong, it's probably not the right hobby for you.

Don't buy an older model, you'll just get frustration and headaches. Buy a current entry-level model not from Bambu Labs. You can find good printers for $300 these days.